In a magnetic resonance imaging apparatus, a radio frequency (RF) coil apparatus serving as a reception coil that comes into contact with a subject is required to have low heat emission to preserve the safety of the subject. In the RF coil apparatus including a plurality of coil elements, in some cases, a plurality of magnetic resonance signals corresponding to the plurality of coil elements are multiplexed, that is, combined, and output to reception circuitry via one coaxial connector. Herewith, the RF coil apparatus executes frequency conversion with respect to the magnetic resonance signals. The frequency conversion is executed in mixer circuitry within the RF coil apparatus. An input power of a local signal input to the mixer circuitry by wide-band matching is required to reach, for example, +10 dBm. Therefore, in some cases, heat may be generated by the local signal at the RF coil apparatus that multiplexes the resonance signals.